Electrophotographic image-forming machines are used to transfer images onto paper or other medium in both printing and copier systems. Generally, a photoconductor is selectively charged and optically exposed to form an electrostatic latent image on the photoconductor surface. Toner is deposited onto the charged photoconductor surface. The toner has a charge; thus, it will adhere to the photoconductor surface in areas corresponding to the electrostatic latent image. The toner image is transferred to the paper or other medium. The toned paper is heated by any of several methods including a fuser roller system and the toner in image-wise configuration is fused to the paper. The photoconductor is then refreshed—cleaned to remove any residual toner and charge—to make it ready for another image. The imaged paper is then passed to a document output collection area or tray where the user collects the finished, permanently imaged paper or documents.
The fuser roll used in the fuser roller system eventually becomes contaminated with a film or debris containing toner or by-products of toner and paper. This contamination usually takes the form of a film which eventually builds up and adversely affects the performance and life of the fuser roll.
This fuser roll contamination can generally occur in any fuser system of an electrophotographic printer or copier, and it causes marks on copy (MOC) in addition to marks caused by prior image history. Generally, the fuser roll becomes contaminated, as earlier noted, with toner and by-products of fuser chemical reactions which eventually can cause early failure of the entire fusing system. There is no known convenient, practical solution to this fuser roll contamination due to competing effects of control factors.
Problems with toner debris on the fuser roller can eventually affect the pressure roll and also the quality and clarity of the imaged paper in contact with the fuser roller. As noted above, the life of the relatively expensive fuser roll can be substantially shortened if this contamination problem is not properly addressed.